User Manual

Siemens Building Technologies CE1N5364E / 09.11.1998
Landis & Staefa Division 1/4
5
364
M-Bus Signal Converter WZC-S250
for plants using a PC as an M-bus central unit
Signal converter designed for the conversion of RS-232 signals to M-bus signals.
The M-bus signal converter is a component of the M-bus system. It serves for the
connection of a PC-M-bus central unit with an RS-232 port to the M-bus.
For the field of use of the M-bus system, please refer to the Basic Documentation
P2900.
•
The M-bus signal converter converts the RS-232 signals to M-bus signals
•
The M-bus signal converter operates as a bus driver
When ordering, please give type reference WZC-S250.
The delivery is comprised of:
–
M-bus signal converter
–
Power pack DC 42 V
The M-bus signal converter is for connection to the RS-232 port of a PC. A maximum of
250 M-bus devices can be connected to the converter.
The M-bus signal converter is for connection between the PC (M-bus central unit) and
an M-bus segment (bus section with M-bus devices).
As a signal converter, the WZC-S250 converts the RS-232 signals to M-bus signals.
For this purpose, the converter is equipped with an RS-232 interface card.
As a bus driver, the WZC-S250 delivers the quiescent current to the connected M-bus
devices. According to standards, the maximum current drawn by an M-bus user is
1.5 mA, representing one "M-bus load". The M-bus output (typically DC 40 V) is
protected against short-circuits.
The interface between the M-bus central unit and the M-bus signal converter is
galvanically separated by an optocoupler.
Power to the M-bus and the RS-232 interface card is delivered by a power pack
(DC 42 V).
Use
Functions
Ordering
Equipment
combinations
Technical design